Apple MD094LL/A manual Run Apple Service Display, Utility to verify the resolution

3.	When display flicker, verify	Yes	Remove glass and LCD panel.
	whether one of the following		Check , reseat, and secure the
	symptoms occurred:		DisplayPort LCD cable to both
•	Flickering image		ends. Check and reseat the
•	Horizontal bands of static		VSync cable to both ends.
			Go to step 4.
	intermittently appear
•	Dock and / or menu bar shift	No	LCD panel OK.
	positions		Go to step 4.

•Display intermittently flashes on / off

4.	Power ON computer and verify	Yes	If connections are secure and
	if issue still occurs.		display is still flickering, go to
			step 5.
		No	Issue resolved.
5.	Carefully disconnect and	Yes	Replace and damaged	X03
	verifiy if any of the four cables		cable(s) and retest.
	on back of LCD panel show
	signs of damage, corrosion, or
		No	Go to step 6.
	pinched wires.
6.	Verify whether flickering occurs	Yes	Image present but backlight
	when brightness level is set		is flickering. Replace Vertical	X03
	below max.		sync cable (between LCD
			panel and LED Backlight
			board) and retest. Replace
			backlight board if problem
			persist.
		No	Replace internal DisplayPort	X03
			cable (between Logic Board
			and LCD panel), retest and go
			to step 7.
7.	Verify if flickering issue is still	Yes	Replace LCD panel.
	present.		Run Apple Service Display	L06
			Utility to verify the resolution
			of issue.
			Enter the resulting verification
			code into the “Notes” field
			of GSX and return system to
			customer if repair is complete
		No	Issue resolved.

2010-09-09 iMac (27-inch, Mid 2010) Symptom Charts — Display  56